Cupola-furnace.



No. 65|,386.- Patented 'lune I2, I900. F. H. RICHARDS.

CUPOLA FURNACE.

(Application: filed Nov. 26, 1898.)

(No Model.)

r U M "m: Nonms PETER! co. Pnmou'ruo WASHINGTON. n, :4

NITED STATES PATENT FFICE.

FRANCIS 1-1. RICHARDS, OF HARTFORD, CONNECTICUT.

CUPOLA-FURNACE.

SPECIFICATION forming part of Letters Patent No. 651,386, dated June 12,1900. Application filed November 26,1898. Serial No. 697,525. (Nomodel.)

To all whom it may concern.-

Be it known that I, FRANCIS H. RICHARDS, a citizen of the United States,residing in Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inGupola-Furnaces, of which the following is a specification.

This invention relates to cupola or analogous furnaces, the objectsthereof being to provide a furnace of this kind especially adapted foruse in making finer grades of castings and to equip said furnace withmeans whereby the process of melting iron can be effectively andeconomically carried out.

In the drawings accompanying and forming part of this specification,Figure 1 is a sectional side elevation of a furnace made in accordancewith my present improvements, and Fig. 2 is a sectional plan view online a (L, Fig. 1.

Similar characters of reference designate like parts in both figures ofthe drawings.

In the drawings the furnace is designated by B, is mounted on the usualsupports 2, and is provided with a floor 3, wind-chest 4:, airsupplychamber 5, and twyers or air-passages between the wind-box and theinterior of the cupola, as is usual.

My improvement involves more especially the combination of aheating-chamber, an air blast pipe communicating with saidheatingchamber, a hot-air chamber connected with the heating-chamber andwith the furnace, and means for supplying liquid to the air near the topof the hot-air chamber before it enters the furnace.

At the top the furnace B is provided with a heating chamber 6,constructed with an outer wall 7, lower wall 9, and top wall or plate10. Within this chamber 6 is a flaring or bell-shaped chamber 8, whichconstitutes the stack for the furnace and communicates at the top withthe atmosphere.

Cold air is brought to the heating-chamber 6 by a supply-pipe l2,entering said chamber at the upper end thereof and above the top portionof a spirally-arranged plate 13, whereby the air will be caused totravel around the chamber 6 and against the wall of the stack 8 thereinand will become thoroughly heated before entering the pipe 5, leading tothe furnace. The air-supply having been heated in the chamber 6 byreason of its circulation therein, as above stated, is then conductedoutof the chamber into the hot-blast pipe 5, which connects with the lowerend of the furnace through the twyers 5.

For the purpose of modifying the character pose the water-supply pipe 15is shown extending into the upper part of the longitudinal andvertically-disposed hot-blast pipe 5, said pipe 15 terminating in arose16, whereby the water enters in the form of spray at or near the upperend of the descending column of hot air, by reason of which the air willbe thoroughly charged with Water and the blast delivered to the furnacewill be a commingled one of air and entrained particles of water at sucha temperature that all danger of chilling or deadening the fire will beavoided.

By means of this improvement, therefore, the furnace may be suppliedwith a hot-air blast which contains water in such a heated state thatthe metal in the furnace will not be chilled nor will the fire bedeadened, which is the ordinary result when water or steam is introducedin the usual manner, and by the use of my invention the air-blast isbrought into a better condition,whereby the formation of gases and thechemical reactions taking place within the furnace are so modified as tocreate a higher quality of iron in the output, especially when this isrun into small castings.

The hot-blastpipe constitutes a chamber in which the water is entrainedby the air before the latterenters the furnace, and this chamber may, ifdesired, be covered externally with non-conducting material M, or itvmay be made entirely of such material for the purpose of reducing orpreventing. the radiation of heat.

Obviously one of the incidental advantages of my present improvements isthe utilization of a considerable proportion of the heat which isordinarily carriedoff from cupola-furnaces in the form of Waste gases.For this purpose the wall of the chamber 8 is shown as of flared orbell-shaped form and is smallest in diameter at its upper end, therebybringing said chamber into a more favorable position for receiving andtransmitting the heat.

In the apparatus shown and described a practical advantage is secured byreason of the fact that the hot-blast pipe or chamber is of considerablelength and is also vertically disposed, whereby the hot air passesrapidly downward and moves along with the spray, and the spray will ofcourse naturally fall by the action of gravity, so that the spray andthe air pass along together in a substantiallyuniform manner. By meansof this particular feature of the improvement a higher degree ofefliciency in the action of the blast is obtained.

The watersupply pipe 15 may be provided with a valve 17, connected by alink 18 with a hand-lever 19, pivoted, as at 20, to the pipe 5, thisorganization constituting a conr'enient means for regulating thequantity of water or other liquid supplied to the said pipe 5, whichwater or other liquid may be introduced in either a hot or a coldcondition, as may be desired.

In the operation of this invention the blast is first turned on, beingheated in the hot-air chamber, until the iron begins to melt, and aboutat the inception of this period the valve 17 is turned to admit aregulated amount of water in the form of spray into the hot-airblastchamber, near the upper end thereof. The drops or particles of waterfall, of course, by gravity, are entrained by the hot-air blast, heatedby the same, and are conveyed under the influence of gravity and theblast into the furnace, where the water is decomposed and resolved intoits elements-oxygen and hydrogen-nearly all of the impurities containedin the charge of pig-iron and scrap (especially the sulfur) being burnedout and eliminated. In this process the hydrogen element of thedecomposed water combines with the oxygen of the air-blast to producewhat is known as the oxyhydrogen flame, by which, with the air-blast theimpurities, which would result in an inferior product if retained, arenot only destroyed, but a large proportion of the carbon contained inthe charge is also burned out, the result being a tough homogeneousproduct having a small percentage of carbon and resembling mild steel ormalleable cast-iron.

Having described my invention, I claim 1. The combination, with afurnace provided with an air-heating chamber, of a hotblast chambercommunicating with said airheating chamber and with the furnace, and

2. The combination, with a furnace and an air-heating chamber, of avertically-disposed pipe communicating, respectively, with saidair-heating chamber and with the furnace; a cold-air pipe leading intosaid air-heating chamber; and a spraying apparatus connected with saidvertically-disposed pipe at a point remote from the place at which thesame connects with the furnace.

3. The combination, with a furnace, of an air-chamber in position to beheated by the waste gases therefrom means for supplying an air-blast tosaid chamber; a hot-blast pipe extending from the heating-chamber to theblast-inlet-of the furnace, and constituting a hot-blast chamber; and awater supply and spray apparatus located near the end of the air-heatingchamber remote from the furnace for charging the hot blast withspray,whereby particles of water at a proper temperature areentrained'in the hot blast before it reaches the furnace.

4. The combination, with a furnace, of an air-heatiu g chamber arrangedto be heated by the waste gases from said furnace; a cold-air pipecommunicating with said chamber; a hot-blast chamber in connection withthe airheating chamber and with the furnace; a liquid-supply devicelocated near the upper end of said hot-blast chamber; and means forregulating the supply of liquid through said device.

5. The combination, with a furnace, of an air-heating chamber arrangedto be heated by the waste products discharged from said f urnace andcontaining a spiral plate; an airblast pipe communicating with theair-heatin g chamber near the top thereof; a hot-blast pipe connectedwith the air-heating chamber at its upper end and with the furnace atits lower end; and a spray-nozzle located near the upper end of thehot-blast pipe.

6. The combination, with a furnace, of an air-heating chamber located atthe top thereof and having a flared or bell-shaped stack communicatingwith the furnace and a spiral plate; a cold-air pipe entering saidair-heating chamber; a hot-blast chamber communicating with theair-heating chamber at its upper end and with the furnace at the lowerend; and a liquid-supply device located near the upper end of saidhot-blast chamber.

FRANCIS II. RICHARDS.

\Vitnesses:

CHAS. T. SOHMELZ, HENRY BIssELL.

